The invention relates to rotary valves and, more particularly, to a new and improved rotary valve arrangement especially adapted for use in internal combustion engines.
Rotary valves have several fundamental advantages over conventional tappet valves for controlling the cylinder intake and exhaust in internal combustion engines. One advantage results from the elimination of inertial forces and impacts, making rotary valves silent and functionally independent of speed. Furthermore, with rotary valve control, large gas flow cross sections can be achieved, which enhances the attainable power output of the engine. To provide the same power output with tappet valves, it would be necessary to provide as many as four inlet valves per cylinder. Moreover, with rotary valves a compact, unitary combustion chamber directly exposed to the intake flow is attainable.
Widespread use of rotary valves to control the intake and exhaust of internal combustion engines has long been hindered by sealing problems. In German Offenlegungschrift No. 2,928,450 and in other patent literature, oil lubrication is provided at or near the sealing means of a rotary valve. Regardless of whether the sealing means in conventional rotary valves comprises sealing strips extending along meridians thereof or, as described in German Offenlegungschrift No. 2,510,005, facing surfaces pressed against the rotary valve member and fitted with gaskets, oil lubrication is necessary. Consequently, the fundamental disadvantages of such rotary valves are high oil consumption and, despite the use of oil lubrication, a high frictional power loss, which adversely affects the efficiency of the engine.
Accordingly, it is an object of the present invention to provide a new and improved rotary valve arrangement which eliminates the disadvantages of the prior art rotary valve arrangments.